Tunable Blow-Off Sound Without the Boost Loss or Stalling on Your S14 and S15
The GFB GFBT9004 TMS Respons Blow Off Valve Kit is engineered for the 1994-2002 Nissan Silvia S14 and S15. Unlike fixed-ratio atmospheric BOVs that can cause backfiring and stalling on modern MAP-sensor-equipped engines, the Respons uses GFB’s patent-pending TMS Technology to let you dial in the balance between atmosphere venting and recirculation. You get the blow-off sound you want without sacrificing boost recovery speed or driveability. The GFBT9004 also includes all the application-specific adapters and fittings needed for a direct-fit installation on the Silvia S14/S15 platform.
Key Features
- GFBT9004 TMS Technology lets you independently adjust the amount of atmosphere venting versus recirculation
- Eliminates the backfiring and stalling caused by fully atmospheric BOVs on MAP-sensor-equipped engines
- Rapid boost recovery on gear shift compared to standard piston-type valves
- Rated to 100+ psi boost capacity for any forced induction application
- Adjustable for both street and performance driving without removing the valve
- Includes Nissan Silvia S14/S15 direct-fit adapter and hoses for bolt-on installation
- Anodized aluminum body construction for durability and heat resistance
- Compatible with both factory and aftermarket turbos on the SR20DET engine
Fitment
| Year Range | Make | Model | Trim |
|---|---|---|---|
| 1994-1998 | Nissan | Silvia | S14 |
| 1999-2002 | Nissan | Silvia | S15 |
Specifications
| Detail | Value |
|---|---|
| Part Number | GFBT9004 |
| Brand | Go Fast Bits (GFB) |
| Application | 1994-2002 Nissan Silvia S14/S15 |
| Valve Type | Blow Off Valve (BOV) |
| Technology | TMS (Turbo Management System) |
| Max Boost Rating | 100 psi+ |
| Body Material | Anodized Aluminum |
| Adjustment | External, tool-free vent ratio adjustment |
| Compatibility | MAP sensor equipped SR20DET, aftermarket turbos |
| UPC | 9318396028793 |
What’s Included
- GFB GFBT9004 TMS Respons BOV body
- Nissan Silvia S14/S15 direct-fit adapter plate
- Inlet and outlet hoses and clamps
- Hardware pack and installation instructions
About Go Fast Bits
Go Fast Bits (GFB) is an Australian-engineered performance valve brand founded in 1997, specializing in blow off valves, diverter valves, and boost controllers. GFB pioneered the TMS (Turbo Management System) technology that allows drivers to tune the vent ratio of their BOV to suit their specific engine management system, eliminating the compromise between sound and driveability that was common with earlier atmospheric valves.
Frequently Asked Questions
Will the GFBT9004 cause backfiring or stalling on my SR20DET-powered Silvia?
No. The GFBT9004’s TMS Technology allows you to blend the atmosphere vent ratio so your MAP sensor does not see a sudden pressure drop that causes the ECU to enrich fueling and cause backfires or stalls. You can tune the sound level while preserving drivability.
Can I run the GFBT9004 fully atmospheric for maximum blow-off sound?
Yes. The Respons can be adjusted to vent fully to atmosphere if your engine management allows it. On cars with MAP-based fueling, full atmospheric venting may cause drivability issues. TMS allows you to find the right balance for your specific tune.
Is the GFBT9004 compatible with the factory SR20DET turbo on the S14 and S15?
Yes. The GFBT9004 is compatible with both the factory IHI RHF5 turbocharger on the Nissan Silvia S14/S15 SR20DET and most common aftermarket turbo upgrades for this platform.
Does the GFBT9004 fit the Nissan 200SX as well as the Silvia?
The GFBT9004 is designed for the S14/S15 Silvia chassis. Fitment on the 200SX (S13 platform) would require different adapters. Verify the application before purchasing for S13-based vehicles.
How do I adjust the vent ratio on the GFBT9004?
The Respons features an external adjustment knob that controls the balance between atmospheric venting and recirculation. Turning it clockwise increases recirculation (quieter, more drivability-friendly). Counterclockwise increases atmosphere venting (louder). Adjustment can be made without tools and without removing the valve.
What boost pressure can the GFBT9004 handle?
The GFB Respons is rated for 100+ psi boost capacity, far exceeding what any factory or typical aftermarket street turbo setup on an S14/S15 Silvia would produce.
Does the GFBT9004 come with all the hoses and fittings needed for my Silvia?
Yes. The GFBT9004 kit includes the direct-fit adapter plate for the Nissan Silvia S14/S15, along with the inlet and outlet hoses, clamps, and all hardware required for installation.
Is the GFBT9004 legal for street use in California?
The GFBT9004 is a BOV/bypass valve modification. Emissions and street legality for BOV modifications vary by state and local jurisdiction. In California, BOV modifications are subject to smog check inspection. Verify local regulations before installing.
Installation Instructions
- Allow the engine to cool before working in the intake/charge pipe area
- Locate the factory BOV on the intake manifold or turbo outlet charge pipe on the Silvia S14/S15
- Remove the factory BOV and adapter port, retaining any reusable hardware
- Attach the GFBT9004 adapter plate to the factory BOV port using the provided hardware
- Connect the GFBT9004 valve body to the adapter plate and secure all hose clamps
- Route and secure the pressure reference line from the intake manifold to the BOV reference port
- Start the vehicle and verify there are no boost leaks at any connection point
- Adjust the vent ratio knob to your preferred setting and test-drive to confirm drivability
WARNING: This product can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and reproductive harm. For more information go to www.P65Warnings.ca.gov.
